JPWO2018221042A1 - Light emitting device and method for manufacturing light emitting device - Google Patents

Abstract

A light emitting device according to an embodiment of the present disclosure includes a stacked body. The stacked body includes an active layer and a first semiconductor layer and a second semiconductor layer that sandwich the active layer. This light emitting device further includes a current constricting layer having an opening, a first reflecting mirror having a concave curved surface on the side of the first semiconductor layer and a second reflecting mirror on the side of the second semiconductor layer, which sandwiches the stacked body and the opening. And a vertical resonator. The light emitting device further includes a light transmissive substrate between the first reflecting mirror and the stacked body. The light transmissive substrate has a convex surface-shaped first convex portion in contact with the first reflecting mirror on the surface opposite to the laminated body, and one or a plurality of second convex portions provided around the first convex portion. Parts. The one or more second convex portions have a height equal to or higher than the height of the first convex portion, and the end portion on the first reflecting mirror side has a convex curved surface shape.

Description

  The present disclosure relates to a light emitting device and a method for manufacturing the light emitting device.

  There is disclosed a technique in which a reflecting mirror of a surface emitting laser is formed into a concave curved surface.

JP-A-3-26302 JP-A-9-11791 JP-T-2013-541854 A

  By the way, when the reflecting mirror of the surface emitting laser has a concave curved surface, it is necessary not only to arrange the optical axis of the surface emitting laser at a predetermined position with respect to the wiring board but also to protect the concave curved reflecting mirror. Can be Therefore, it is desirable to provide a light emitting element and a method for manufacturing the light emitting element that can align with the wiring board and protect the concave curved reflecting mirror.

  A light emitting device according to an embodiment of the present disclosure includes a laminate. The stacked body includes an active layer, and a first semiconductor layer and a second semiconductor layer sandwiching the active layer. The light-emitting element further includes a current confinement layer having an opening, a first reflecting mirror having a concave curved surface on the first semiconductor layer side and a second reflecting mirror on the second semiconductor layer side sandwiching the stacked body and the opening. Vertical resonator. The first reflecting mirror has a concave curved surface curved to the opposite side to the laminate. The light emitting device further includes a light transmitting substrate between the first reflecting mirror and the laminate. The light-transmitting substrate has a first convex portion having a convex curved surface in contact with the first reflecting mirror, and one or more second convex portions provided around the first convex portion on a surface opposite to the laminate. Part. The one or more second protrusions have a height equal to or higher than the height of the first protrusion, and the end on the first reflecting mirror side has a convex curved shape. The end of the second convex portion on the first convex portion side has a convex curved surface shape protruding toward the first convex portion.

  In the light-emitting element according to an embodiment of the present disclosure, a first convex portion having a convex curved surface that is in contact with the first reflecting mirror is provided on a surface of the light-transmitting substrate opposite to the laminate. The light-transmitting substrate further includes one or more second protrusions having a height equal to or higher than the height of the first protrusions around the first protrusions. In one or a plurality of second convex portions, the end on the first reflecting mirror side has a convex curved shape. Thereby, the mounting position of the light emitting element is determined by the self-alignment function of the convex curved surface of the second convex portion or the convex curved surface of the layer formed following the convex curved surface of the second convex portion. Further, during the manufacturing process and the mounting process of the light emitting element, the first convex portion is protected by the second convex portion.

  A method for manufacturing a light emitting device according to an embodiment of the present disclosure includes a resist forming step, a reflow step, and a convex part forming step. In the resist forming step, first, on the first main surface of the light transmitting substrate, a stacked body including an active layer, a first semiconductor layer and a second semiconductor layer sandwiching the active layer, and a current confinement layer having an opening are provided. A light emitting element substrate having the following is prepared. Next, a first resist layer is formed on the second main surface of the light-transmitting substrate opposite to the first main surface at a location facing the opening, and the first resist layer is formed around the location facing the opening. One or more second resist layers are formed. In the reflow step, the first resist layer and the one or more second resist layers are reflowed to make the surface of the first resist layer convex and curved, and the one or more second resist layers are At least the end of the surface on the first resist layer side is formed into a convex curved surface. In the protruding portion forming step, dry etching using a resist etch-back method is performed using the first resist layer after the reflow and the one or more second resist layers as a mask, so that the second main surface of the substrate is formed. Forming a first convex portion having a convex curved surface at a position where the first resist layer is formed, and forming a second convex portion having a convex curved surface at a position where one or a plurality of second resist layers are formed. I do. In the resist forming step, the width of each of the first resist layer and the one or more second resist layers is such that the height of each second protrusion is equal to or greater than the height of the first protrusion by reflow and resist etchback. It is set as follows.

  In the method for manufacturing a light emitting device according to an embodiment of the present disclosure, reflow is performed on the first resist layer and one or more second resist layers provided on the second main surface of the substrate. As a result, the surface of the first resist layer becomes a convex curved surface, and at least one end of the surface of the one or more second resist layers on the first resist layer side becomes a convex curved surface. Further, dry etching using a resist etch-back method is performed using the first resist layer after the reflow and one or more second resist layers as a mask. Thereby, on the second main surface of the substrate, a first convex portion having a convex curved surface is formed at the place where the first resist layer was formed, and at the place where one or a plurality of second resist layers are formed, At least one or more second convex portions having a convex curved surface at least on the first resist layer end are formed. When the resist is formed, the width of each of the first resist layer and the one or more second resist layers is such that the height of each second convex portion is equal to or greater than the height of the first convex portion by reflow and resist etchback. Is set to be Thus, the mounting position of the light emitting element is determined by the self-alignment function of the convex curved surface of the second convex portion or the convex curved surface of the layer formed following the convex curved surface of the second convex portion. Further, during the manufacturing process and the mounting process of the light emitting element, the first convex portion is protected by the second convex portion.

  According to the light emitting device and the method for manufacturing the light emitting device according to an embodiment of the present disclosure, the self-alignment by the convex curved surface of the second convex portion or the convex curved surface of the layer formed following the convex curved surface of the second convex portion. With the function, the mounting position of the light emitting element can be determined, and the first convex portion can be protected by the second convex portion during the manufacturing process and the mounting process of the light emitting device. The positioning with respect to the substrate can be performed with high accuracy, and the concave mirror can be protected. Note that the effects of the present disclosure are not necessarily limited to the effects described here, and may be any of the effects described in this specification.

1 is a diagram illustrating a cross-sectional configuration example of a light emitting element according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a top configuration of the light emitting device of FIG. 1. It is a figure showing an example of a lens diameter, a lens height, and a radius of curvature. FIG. 2 is a diagram illustrating an example of a manufacturing procedure of the light emitting device of FIG. 1. FIG. 2 is a diagram illustrating an example of a manufacturing process of the light-emitting element in FIG. 1. FIG. 6 is a diagram illustrating an example of a manufacturing process following FIG. 5. FIG. 7 is a diagram illustrating an example of a manufacturing process following FIG. 6. FIG. 8 is a diagram illustrating an example of a manufacturing process following FIG. 7. FIG. 9 is a diagram illustrating an example of a manufacturing process following FIG. 8. FIG. 10 is a diagram illustrating an example of a manufacturing process following FIG. 9. FIG. 11 is a diagram illustrating an example of a manufacturing process following FIG. 10. FIG. 12 is a diagram illustrating an example of a manufacturing process following FIG. 11. FIG. 2 is a diagram illustrating an example of mounting the light emitting device of FIG. 1 on a wiring board. FIG. 4 is a diagram illustrating a modification of the light emitting device of FIG. 2. FIG. 15 is a diagram illustrating an example of a manufacturing process of the light emitting device of FIG. 14. FIG. 4 is a diagram illustrating a modification of the light emitting device of FIG. 2. FIG. 17 is a diagram illustrating an example of a manufacturing process of the light emitting device of FIG. 16. FIG. 4 is a diagram illustrating a modification of the light emitting device of FIG. 1. FIG. 19 is a diagram illustrating a configuration example of a top surface of the light emitting element of FIG. 18. FIG. 4 is a diagram illustrating a modification of the light emitting device of FIG. 2. FIG. 4 is a diagram illustrating a modification of the light emitting device of FIG. 2.

Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following embodiments. In addition, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, and the like of each component illustrated in each drawing. The description will be made in the following order.

1. Embodiment 1. Example in which island-shaped protrusions are formed around a vertical resonator Modification A Modification A: An example in which a vertical resonator is formed at the center position of an annular protrusion Modification B: An example in which an annular protrusion is divided into a plurality and formed around the vertical resonator Modification Example C: An example in which a bump is formed around a vertical resonator

<1. Embodiment>
[Constitution]
The light emitting device 1 according to an embodiment of the present disclosure will be described. FIG. 1 illustrates a cross-sectional configuration example of the light-emitting element 1. FIG. 2 illustrates an example of a top configuration of the light emitting element 1.

The light-emitting element 1 is a top-emitting semiconductor laser that can be suitably applied to applications requiring thinness and low power consumption and applications requiring a thin and large area. The light emitting element 1 has a vertical resonator. The vertical resonator is configured to oscillate at a predetermined oscillation wavelength λ ₀ by two DBRs (distributed Bragg reflectors) facing each other in the normal direction of the substrate 11. The vertical resonator is constituted by two DBR layers sandwiching the substrate 11, the stacked body 12, and the opening 13A of the current confinement layer 13. That is, the substrate 11 is a substrate provided inside the vertical resonator, and is a substrate provided between one DBR layer and the stacked body 12. The two DBR layers are constituted by a DBR layer 18 (first reflecting mirror) on the semiconductor layer 12a side described later and a DBR layer 16 (second reflecting mirror) on the semiconductor layer 12c side described later. The DBR layer 18 is formed in contact with the back surface of the substrate 11. The stacked body 12 includes, for example, an active layer 12b and two semiconductor layers sandwiching the active layer 12b. The two semiconductor layers include a semiconductor layer 12a close to the substrate 11 and a semiconductor layer 12c remote from the substrate 11.

  In the light emitting element 1, for example, a semiconductor layer 12a, an active layer 12b, a semiconductor layer 12c, a current confinement layer 13, an electrode layer 14, electrode pads 15, 17 and a DBR layer 16 are formed on a substrate 11 in this order from the substrate 11 side. Have. The light emitting element 1 further includes, for example, a DBR layer 18 and a metal layer 19 on the rear surface side of the substrate 11 in this order from the substrate 11 side. The stacked body 12 may have, for example, a contact layer on the outermost surface on the semiconductor layer 12c side for bringing the semiconductor layer 12c and the electrode layer 14 into ohmic contact with each other. The contact layer may be a layer formed by doping the outermost surface of the semiconductor layer 12c with a high concentration impurity, or may be formed on the outermost surface of the semiconductor layer 12c formed separately from the semiconductor layer 12c. It may be a layer in contact.

The substrate 11 is a crystal growth substrate used when epitaxially growing the stacked body 12. The substrate 11 and the stacked body 12 are made of a gallium nitride-based semiconductor. The substrate 11 is a light-transmitting substrate, for example, a GaN substrate. The laminate 12 is made of, for example, GaN, AlGaN, AlInN, GaInN, AlGaInN, or the like. The semiconductor layer 12a is made of, for example, GaN. The semiconductor layer 12a contains, for example, silicon (Si) as an n-type impurity. That is, the semiconductor layer 12a is an n-type semiconductor layer. The semiconductor layer 12c is made of, for example, GaN. The semiconductor layer 12c contains, for example, magnesium (Mg) or zinc (Zn) as a p-type impurity. That is, the semiconductor layer 12c is a p-type semiconductor layer. The active layer 12b has, for example, a quantum well structure. Examples of the type of the quantum well structure include a single quantum well structure (QW structure) and a multiple quantum well structure (MQW structure). The quantum well structure has a structure in which well layers and barrier layers are alternately stacked. The combination of the well layers and barrier layers, for _{example, (In y Ga (1-} y) N, GaN), (In y Ga (1-y) N, In z Ga (1-z) N) [ where, y> z], (In _y Ga _(1-y) N, AlGaN) and the like.

  The current confinement layer 13 is a layer for constricting a current injected into the active layer 12b. The current confinement layer 13 is composed of, for example, an insulating layer having an opening 13A. The insulating layer is formed, for example, in contact with the outermost surface of the laminate 12 and is made of, for example, an inorganic material such as SiO2. Note that the insulating layer may be formed of a high-resistance region formed by injecting impurities into the stacked body 12 from the semiconductor layer 12c side of the stacked body 12. The light emitting element 1 may have a function equivalent to that of the current confinement layer 13 instead of the current confinement layer 13. The light emitting element 1 may include, for example, a contact layer having the same size as the opening 13A between the semiconductor layer 12c and the electrode layer 14. Such a contact layer is formed, for example, by forming a contact layer on the entire surface of the semiconductor layer 12c and then selectively etching the same by RIE (Reactive Ion Etching) or the like. By providing such a contact layer, current confinement can be performed. In addition, the light emitting element 1 is formed, for example, by forming a layered body 12 into a column shape by performing dry etching with a mask on a portion to be the light emitting unit 10 in the layered body 12, and then forming the columnar stacked body 12. It may have an annular oxidized region formed by partial oxidation from the lateral direction. By providing such an oxidized region, current constriction can be performed. The opening 13A has, for example, a circular shape. The diameter of the opening 13A is, for example, about 10 μm.

  The electrode layer 14 is in contact with the surface of the laminate 12 that is exposed at the bottom surface of the opening 13A of the current constriction layer 13. The electrode layer 14 is made of, for example, a transparent conductive material. Examples of the transparent conductive material used for the electrode layer 14 include ITO (Indium Tin Oxide). The electrode pad 15 is electrically connected to an external electrode or circuit, and is electrically connected to the electrode layer 14. The electrode pad 15 is in contact with, for example, a portion of the electrode layer 14 that is not opposed to the opening 13A. The electrode pad 15 is made of, for example, Pd / Ti / Pt / Au, Ti / Pd / Au, Ti / Ni / Au, Ni / Au, or the like.

  The electrode pad 17 is electrically connected to an external electrode or circuit, and is electrically connected to the semiconductor layer 12a. The current confinement layer 13 has an opening 13B in a region around the vertical resonator. The stacked body 12 has a groove at a position facing the opening 13B, and the semiconductor layer 12a is exposed at the bottom of the groove. The electrode pad 17 is in contact with the semiconductor layer 12a via the opening 13B of the current confinement layer 13 and the groove of the stacked body 12. The electrode pad 17 is in contact with, for example, a portion of the semiconductor layer 12c that is not opposed to the opening 13A. The electrode pad 17 is made of, for example, Pd / Ti / Pt / Au, Ti / Pd / Au, Ti / Ni / Au, or the like. The electrode pad 17 may be electrically connected to the semiconductor layer 12a via another member. For example, when the substrate 11 is made of a conductive material such as a GaN substrate, the electrode pad 17 may be electrically connected to the semiconductor layer 12a via the substrate 11. In this case, the electrode pad 17 may be provided on the back surface of the substrate 11 (a flat surface 11S described later).

Each of the DBR layers 16 and 18 is composed of, for example, a dielectric multilayer film. The dielectric multilayer film has a structure in which low refractive index layers and high refractive index layers are alternately laminated. The thickness of the low refractive index layer is preferably an odd multiple of λ ₀ / 4n ₁ (n ₁ is the refractive index of the low refractive index layer). The thickness of the high refractive index layer is preferably an odd multiple of λ ₀ / 4n ₂ (n ₂ is the refractive index of the high refractive index layer). Examples of the material of the dielectric multilayer film forming the DBR layers 16 and 18 include SiO ₂ , SiN, Al ₂ O ₃ , Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , AlN, MgO, and ZrO _2. Can be In the dielectric multilayer films constituting the DBR layers 16 and 18, as the combination of the low refractive index layer and the high refractive index layer, for example, SiO ₂ / SiN, SiO ₂ / Nb ₂ O ₅ , SiO ₂ / ZrO ₂ , SiO ₂ / AlN, SiO ₂ / Ta ₂ O _{5 and the} like. The dielectric multilayer films constituting the DBR layers 16 and 18 are formed by, for example, a film forming method such as sputtering, CVD, or vapor deposition.

  The metal layer 19 is formed in contact with the surface of the DBR layer 18, and is formed, for example, in contact with the entire surface of the DBR layer 18. The metal layer 19 is formed following the surface of the DBR layer 18. The metal layer 19 is made of, for example, Pd / Ti / Pt / Au, Ti / Pd / Au, Ti / Ni / Au, or the like. When the DBR layer 18 is partially provided with an opening, the metal layer 19 may be electrically connected to the semiconductor layer 12a via the substrate 11 exposed in the opening of the DBR layer 18. Good. In that case, the metal layer 19 can have the same function as the electrode pad 17.

  The substrate 11 has a convex portion 11A (first convex portion) protruding on the opposite side to the laminate 12 on the back surface. The projection 11A is provided at a position facing the opening 13A. The entire surface of the convex portion 11 </ b> A has a convex curved surface protruding on the opposite side to the laminate 12. It is preferable that the radius of curvature of the surface of the convex portion 11A is larger than the resonator length of the vertical resonator. This is because, when the radius of curvature of the surface of the convex portion 11A is smaller than the length of the resonator in the vertical resonator, the optical field confinement becomes excessive and light loss is likely to occur.

  The substrate 11 further has a plurality of convex portions 11B (second convex portions) protruding on the opposite side to the stacked body 12 on the back surface. The plurality of protrusions 11B are provided so as to avoid positions facing the openings 13A, and specifically, are provided around the protrusions 11A. The plurality of protrusions 11B are arranged, for example, at point-symmetric positions with respect to the protrusion 11A. Each convex portion 11B has an island shape, for example, a circular shape, an elliptical shape, or a polygonal shape when viewed from the normal direction of the substrate 11. The convex portion 11B has a height equal to or higher than the height of the convex portion 11A, and at least the surface of the end portion on the convex portion 11A side has a convex curved shape. The entire surface of the convex portion 11 </ b> B may have a convex curved shape protruding on the opposite side to the laminate 12. Here, the end of the convex portion 11B on the convex portion 11A side has a convex curved surface shape protruding toward the convex portion 11A side. The height of the protrusions 11A and 11B refers to the height of the rear surface of the substrate 11 from the flat surface 11S corresponding to the base of the protrusions 11A and 11B.

  As described above, the metal layer 19 is formed following the surface of the DBR layer 18. Therefore, the portion of the metal layer 19 facing the convex portion 11A is curved following the surface of the DBR layer 18 to form the convex portion 10A protruding on the opposite side to the stacked body 12. Further, a portion of the metal layer 19 facing the convex portion 11B is also curved following the surface of the DBR layer 18, and constitutes a convex portion 10B protruding on the opposite side to the stacked body 12. The protrusion 10B has a height equal to or higher than the height of the protrusion 10A, and the surface of the end on the protrusion 10A side has a convex curved shape. The entire surface of the convex portion 10B has, for example, a convex curved shape protruding on the opposite side to the laminate 12. Here, the height of the projections 10A and 10B refers to the height from the flat surface 11S corresponding to the base of the projections 11A and 11B on the back surface of the substrate 11.

  FIG. 3 illustrates an example of the relationship between the lens diameter, the lens height, and the radius of curvature. The lens diameter refers to the diameter of the protrusion 11A and the protrusion 11B. The lens height refers to the height of the convex portions 11A and 11B. The radius of curvature refers to the radius of curvature of the surfaces of the convex portions 11A and 11B.

  As described above, the protrusion 11B has a height equal to or higher than the height of the protrusion 11A. The heights of the protrusions 11A and 11B are formed by etching the substrate 11 using the reflowed island-shaped resist layer as a mask, as described later. The diameter of the reflowed island-shaped resist layer corresponds to the lens diameter in FIG. That is, by changing the diameter of the reflowed island-shaped resist layer, the height and the radius of curvature of the convex portions 11A and 11B can be adjusted.

  It is assumed that the diameter of the island-shaped resist layer used for forming the convex portion 11B is smaller than the diameter of the island-shaped resist layer used for forming the convex portion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the convex portion 11A is 80 μm, and the diameter of the island-shaped resist layer used for forming the convex portion 11B is 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A is 80 μm, the diameter of the projection 11B is 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B is smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the diameter of the island-shaped resist layer used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer used for forming the protrusion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the convex portion 11A is 30 μm, and the diameter of the island-shaped resist layer used for forming the convex portion 11B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A is 30 μm, the diameter of the projection 11B is 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B is larger than the radius of curvature of the projection 11A.

The DBR layer 18 is formed at least following the surface of the convex portion 11A, and functions as a concave curved reflecting mirror for the vertical resonator. The DBR layer 18 has a concave curved surface curved to the opposite side to the laminate 12. The DBR layer 18 may be formed following the entire surface including the surfaces of the protrusions 11A and 11B. FIG. 1 illustrates a case where the DBR layer 18 is formed following the entire surface including the surfaces of the protrusions 11A and 11B. On the other hand, the DBR layer 16 is formed following the surface of the electrode layer 14 and is formed in contact with the surface of the electrode layer 14. The portion of the DBR layer 16 that faces the opening 13A in the DBR layer 16 is substantially flat. The active layer 12b is preferably arranged closer to the DBR layer 16 and the current confinement layer 13 than the DBR layer 18. Thereby, confinement of the light field in the active layer 12b is enhanced, and laser oscillation is facilitated. Also, from the area center of gravity of the current confinement layer 13, it is preferable that the shortest distance D _CI to the inner edge of the opening portion 13A meets the following expression. As a result, a region where the light reflected by the DBR layer 18 is collected is included in a region where the active layer 12b has a gain by current injection, stimulated emission of light from carriers is promoted, and laser oscillation is performed. This becomes easy. The derivation of the following equation is disclosed in, for example, H. Kogelnik and T. Li, "Laser Beams and Resonators", Applied Optics / Vol. 5, No. 10 / October 1966. Ω ₀ is also called a beam waist radius.

D _CI ≧ ω _0/2
However,
ω ₀ ² ≡ (λ ₀ / π) ｛L _OR (R _DBR −L _OR )｝ ^1/2
here,
λ ₀ : oscillation wavelength L _OR : resonator length R _DBR : radius of curvature of DBR layer 18 (= radius of curvature of surface of convex portion 11A)

[Production method]
Next, a method for manufacturing the light emitting device 1 according to the present embodiment will be described. FIG. 4 illustrates an example of a procedure for manufacturing the light-emitting element 1. 5 to 13 show an example of a manufacturing process of the light-emitting element 1. FIG. First, a stacked body 12 is formed on the surface (first main surface) of the substrate 11 by an epitaxial crystal growth method such as a metal organic chemical vapor deposition (MOCVD) method (FIG. 5). Next, a current confinement layer 13 having an opening 13A is formed on the surface of the laminate 12 by, for example, a CVD (chemical vapor deposition) method, a sputtering method, a vapor deposition method, or ion implantation (FIG. 6). Further, after forming the electrode layer 14 so as to cover the opening 13A by, for example, a sputtering method or an evaporation method, the DBR layer 16 is formed on the electrode layer 14 by, for example, a CVD method, a sputtering method, an evaporation method, or the like. (FIG. 6). For forming the electrode layer 14 and the DBR layer 16, for example, an etching method such as a wet etching method or a dry etching method, or a pattern forming method such as a lift-off method is used.

  Next, an electrode pad 15 is formed so as to be in contact with an end of the electrode layer 14 by, for example, an evaporation method (FIG. 7). Next, an opening 13B is formed in the current confinement layer 13 by, for example, a wet etching method or a dry etching method, and a groove is formed in the stacked body 12 until the semiconductor layer 12a is exposed (FIG. 7). Thereafter, the electrode pad 17 is formed by, for example, an evaporation method (FIG. 7). At this time, the electrode pad 17 is formed so as to be in contact with the semiconductor layer 12a via the opening 13B formed in the current confinement layer 13 and the groove formed in the stacked body 12.

  Next, the support substrate 22 is bonded to the surface including the electrode pads 15 and 17 via the adhesive layer 21. Thereafter, the rear surface (second main surface) of the substrate 11 opposite to the front surface (first main surface) is mirror-finished by, for example, etching such as CMP (Chemical Mechanical Polishing) or polishing by a grinder ( FIG. 8, step S101). It is preferable that the thickness of the substrate 11 is 100 μm or less. The unevenness level on the back surface of the substrate 11 is preferably Rms = 10 nm or less, more preferably 1 nm or less. Next, a resist pattern is formed on the back surface of the polished substrate 11. As a result, a resist layer 23A (first resist layer) is formed in an island shape at a location facing the opening 13A, and two or more resist layers 23B (second A resist layer) is formed in an island shape (FIG. 9, step S102).

  At this time, the resist layers 23A and 23B have, for example, a circular shape, an elliptical shape, and a polygonal shape when viewed from the normal direction of the support substrate 22. The widths R1 and R2 of the resist layers 23A and 23B are different from each other. The widths R1 and R2 of the resist layers 23A and 23B are set so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A by reflow and resist etch-back described later. Specifically, the widths R1 and R2 of the resist layers 23A and 23B are set based on the relationship shown in FIG. 3 so that the height of the protrusion 11B is equal to or greater than the height of the protrusion 11A.

  A design is assumed in which the diameter of the island-shaped resist layer 23B used for forming the convex portion 11B is smaller than the diameter of the island-shaped resist layer 23A used for forming the convex portion 11A. For example, the width R1 of the resist layer 23A is set to 80 μm, and the width R2 of the resist layer 23B is set to 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the protrusion 11B formed by the island-shaped resist layer 23B can be formed higher than the protrusion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A is 80 μm, the diameter of the projection 11B is 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B is smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the diameter of the island-shaped resist layer 23B used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer 23A used for forming the protrusion 11A. For example, it is assumed that the width R1 of the resist layer 23A is 30 μm and the width R2 of the resist layer 23B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B formed by the island-shaped resist layer 23B can be formed higher than the protrusion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A is 30 μm, the diameter of the projection 11B is 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B is larger than the radius of curvature of the projection 11A.

  Next, reflow is performed on the resist layer 23A and the plurality of resist layers 23B (FIG. 10, step S103). Thereby, the surface of the resist layer 23A is formed into a convex curved surface, and at least the end portion on the resist layer 23A side of the surfaces of the plurality of resist layers 23B is formed into a convex curved surface. For example, the entire surface of the resist layers 23A and 23B is formed into a convex curved surface. At this time, the height of the resist layer 23B is equal to or higher than the height of the resist layer 23A. The reflow conditions vary depending on the material and thickness of the resist layers 23A and 23B, but are set to, for example, a temperature of about 150 ° C. to 200 ° C. and a time of about 5 minutes to 15 minutes.

  Next, dry etching is performed on the substrate 11 using the resist layers 23A and 23B having convex curved surfaces as masks (FIG. 11, step S104). That is, dry etching is performed on the substrate 11 by using the resist etch-back method using the reflowed resist layers 23A and 23B as a mask. At this time, it is preferable to make the etching rate of the substrate 11 and the etching rate of the resist layers 23A and 23B as equal as possible. By using such a resist etch-back method, it is possible to form convex portions 11A and 11B on the back surface of the substrate 11 that are very similar to the surface shapes of the resist layers 23A and 23B. Specifically, the convex portion 11A having a convex curved shape can be formed at the position where the resist layer 23A was formed, and at least the end portion on the convex portion 11A side is formed at the position where each resist layer 23B is formed. Can form a convex portion 11B having a convex curved surface. As a result, the height of each protrusion 11B is equal to or higher than the height of the protrusion 11A.

  Next, the DBR layer 18 is formed on the entire surface including the surfaces of the protrusions 11A and 11B by, for example, a CVD method, a sputtering method, or an evaporation method (FIG. 12, step S105). Subsequently, the metal layer 19 is formed on the entire surface of the DBR layer 18 by, for example, a sputtering method or an evaporation method (FIG. 12, step S105). At this time, in the metal layer 19, the height of the portion (convex portion 10B) facing the convex portion 11B is equal to or greater than the height of the portion (convex portion 10A) facing the convex portion 11A. In the metal layer 19, the surface of the end of the protrusion 10B on the side of the protrusion 10A has a convex curved shape. In the metal layer 19, the entire surface of the projection 10B has a convex curved surface. In this way, two DBR layers 16 and 18 (vertical resonators) sandwiching the substrate 11 (specifically, the protrusion 11A), the stacked body 12, and the opening 13A of the current confinement layer 13 are formed. At the same time, the light emitting section 10 having the vertical resonator is formed. Thereafter, the adhesive layer 21 and the support substrate 22 are separated from the surface including the electrode pads 15 and 17, and the substrate 11 is cut into a predetermined size. Thus, the light emitting device 1 is manufactured.

  Note that the method for manufacturing the light emitting element 1 is not limited to the above method. For example, the support substrate 22 may be peeled off after the back surface of the substrate 11 is mirror-finished, and the protrusions 11A and 11B, the DBR layer 18, the metal layer 19, and the like may be formed without the support substrate 22.

[Implementation]
FIG. 13 illustrates an example of mounting the light emitting element 1 on the wiring board 30. The wiring substrate 30 has a plurality of electrode pads 31 on the surface. The in-plane layout of the plurality of electrode pads 31 is, for example, common to the in-plane layout of the plurality of protrusions 11B (or the protrusions 10B). The light emitting element 1 is mounted on the wiring board 30 with the plurality of protrusions 10B facing the wiring board 30 side. The plurality of protrusions 10B are fixed to the plurality of electrode pads 31 via the solder bumps 32. At the time of mounting, the light emitting element 1 is positioned by the self-alignment function by the convex curved surface of each convex portion 10B that is in contact with the solder bump 32 in the molten state. Therefore, the optical axis AX of the light emitting element 1 can be accurately arranged at a predetermined position with respect to the wiring board 30. In addition, since the height of each protrusion 10B is equal to or greater than the height of the protrusion 10A, for example, in the process of mounting the light emitting element 1 on the wiring board 30, each protrusion 11B protects the protrusion 11A. Can play a role.

[motion]
In the light emitting device 1 having such a configuration, when a predetermined voltage is applied between the electrode pad 15 electrically connected to the semiconductor layer 12c and the electrode pad 17 electrically connected to the semiconductor layer 12a. Then, a current is injected into the active layer 12b through the opening 13A, thereby causing light emission due to recombination of electrons and holes. This light is reflected by the pair of DBR layers 16 and 18, and laser oscillation occurs at a predetermined oscillation wavelength λ ₀ . Then, the light leaked from the DBR layer 16 is output to the outside as a beam-like laser light. At this time, when the stacked body 12 is made of a nitride-based semiconductor material, for example, blue-based laser light is emitted from the DBR layer 16 to the outside. When an opening is partially provided in the DBR layer 18, the metal layer 19 is electrically connected to the semiconductor layer 12 a via the substrate 11 exposed in the opening of the DBR layer 18, The metal layer 19 can have the same function as the electrode pad 17.

[effect]
Next, effects of the light emitting element 1 according to the present embodiment will be described.

  When the reflecting mirror of the surface emitting laser has a concave curved surface, it is required not only to dispose the optical axis of the surface emitting laser at a predetermined position with respect to the wiring board but also to protect the concave curved reflecting mirror. For example, in the invention described in Patent Literature 1, an opening is formed by etching a portion immediately below a light emitting element in a substrate, and lens processing is performed on a bottom surface of the opening. Thereby, the lens can be protected, but in order to form an opening in the substrate, it is necessary to dig the substrate to a depth of several tens to several hundreds μm. Therefore, the technical difficulty is high and it is not suitable for mass production. Further, since etching damage remains on the bottom surface of the opening, the bottom surface of the opening is not suitable for forming a lens. Further, when mounting the light emitting element, it is not known whether a portion of the substrate corresponding to the edge of the opening can be used for positioning.

  On the other hand, in the present embodiment, on the surface of the substrate 11 on the side opposite to the stacked body 12, a convex curved surface convex portion 11A that is in contact with the DBR layer 18 and faces the opening 13A is provided. The substrate 11 is further provided with a plurality of protrusions 11B having a height equal to or higher than the height of the protrusion 11A around the protrusion 11A. In each of the protrusions 11B, the surface of the end on the side of the protrusion 11A has a convex curved shape. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function of the convex curved surface of the metal layer 19 (the convex portion 10B) formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. As a result, the alignment of the light emitting element 1 with respect to the wiring board 30 can be performed accurately, and the DBR layer 18 can be protected.

  Further, in the present embodiment, the convex portions 11A and the respective convex portions 10B have an island shape. Thereby, for example, by performing the resist etchback using the relationship shown in FIG. 3, not only the height of each protrusion 11B can be made higher than the height of the protrusion 11A, but also the height of the protrusion 11A and each protrusion 11B can be reduced. They can be formed collectively. As a result, the light emitting element 1 can be accurately positioned with respect to the wiring board 30 without increasing the number of manufacturing procedures, and the DBR layer 18 can be protected. Further, since the protrusions 11A and the respective protrusions 10B can be formed at the same time, it is possible to avoid deterioration in roughness due to damage due to unnecessary etching. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In the present embodiment, the substrate 11 is a GaN substrate. Thereby, for example, by performing the resist etchback using the relationship shown in FIG. 3 on the GaN substrate, not only the height of each of the protrusions 11B but also the height of the protrusions 11A can be increased. Each projection 11B can be formed collectively. As a result, the light emitting element 1 can be accurately positioned with respect to the wiring board 30 without increasing the number of manufacturing procedures, and the DBR layer 18 can be protected. Further, since the protrusions 11A and the respective protrusions 10B can be formed at the same time, it is possible to avoid deterioration in roughness due to damage due to unnecessary etching. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In the present embodiment, in the manufacturing process, reflow is performed on the island-shaped resist layer 23A and the plurality of island-shaped resist layers 23B provided on the back surface of the substrate 11. Thereby, the surface of the resist layer 23A has a convex curved shape, and at least the end on the resist layer 23A side among the surfaces of the plurality of resist layers 23B has a convex curved shape. Further, dry etching using a resist etch-back method is performed using the resist layer 23A and the plurality of resist layers 23B after the reflow as a mask. As a result, on the back surface of the substrate 11, the convex portion 11A having a convex curved surface is formed at the position where the resist layer 23A was formed, and at least the end on the resist layer 23A side is formed at the position where the plurality of resist layers 23B are formed. A plurality of convex portions 11B having convex portions are formed. The widths R1 and R2 of the resist layer 23A and the plurality of resist layers 23B are set by reflow and resist etch-back so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function by the convex curved surface of the metal layer 19 formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. Therefore, it is possible to accurately position the light emitting element 1 with respect to the wiring substrate 30 without increasing the number of manufacturing procedures, and to protect the DBR layer 18. Further, since the protrusions 11A and the respective protrusions 10B can be formed at the same time, it is possible to avoid deterioration in roughness due to damage due to unnecessary etching. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In the present embodiment, in the manufacturing process, one resist layer 23A is formed, two or more resist layers 23B are formed, and further, the resist layer 23A and each resist layer 23B are formed in an island shape. Thus, the height of each convex portion 11B can be made higher than the height of the convex portion 11A only by setting the respective widths R1 and R2 of the resist layer 23A and the plurality of resist layers 23B to desired values. Therefore, the alignment with respect to the light emitting element 1 wiring board 30 can be performed accurately and the DBR layer 18 can be protected without increasing the manufacturing procedure. Further, since the protrusions 11A and the respective protrusions 10B can be formed at the same time, it is possible to avoid deterioration in roughness due to damage due to unnecessary etching. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

<2. Modification>
Next, a modified example of the light emitting element 1 of the above embodiment will be described.

[Modification A]
FIG. 14 illustrates a modification of the light emitting device 1. In this modification, only one convex portion 11B is provided. In the present modification, the protrusion 11B has a ring shape. The convex portion 11B has, for example, a ring shape, an elliptical ring shape, or a polygonal ring shape. The protrusion 11A is arranged in the opening of the protrusion 11B. The protrusion 11B is provided so as to avoid a position facing the opening 13A, and is provided around the protrusion 11A. The convex portion 11B is arranged, for example, at a point-symmetric position with respect to the convex portion 11A. The convex portion 11B has a height equal to or higher than the height of the convex portion 11A, and at least the surface of the end portion (the inner peripheral end portion) on the side of the convex portion 11A has a convex curved shape. The entire surface of the convex portion 11B may have a convex curved surface shape protruding to the opposite side to the laminate 12 in the width direction of the convex portion 11B.

  As will be described later, the height of the protrusion 11B is formed by etching the substrate 11 using the reflowed ring-shaped resist layer as a mask. The width of the reflowed ring-shaped resist layer corresponds to the lens diameter in FIG. That is, by changing the width of the reflowed ring-shaped resist layer, the height and the radius of curvature in the width direction of the protrusion 11B can be adjusted.

  It is assumed that the width of the ring-shaped resist layer used for forming the protrusion 11B is smaller than the diameter of the island-shaped resist layer used for forming the protrusion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the convex portion 11A is 80 μm, and the width of the ring-shaped resist layer used for forming the convex portion 11B is 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A is 80 μm, the width of the projection 11B is 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B is smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the width of the ring-shaped resist layer used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer used for forming the protrusion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the protrusion 11A is 30 μm, and the width of the ring-shaped resist layer used for forming the protrusion 11B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A becomes 30 μm, the width of the projection 11B becomes 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B becomes larger than the radius of curvature of the projection 11A.

  The protrusions 11A and 11B are formed, for example, as follows. First, as shown in FIG. 8, the back surface of the substrate 11 is mirror-finished. Next, a resist pattern is formed on the back surface of the polished substrate 11. As a result, a resist layer 23A (first resist layer) is formed in an island shape at a position facing the opening 13A, and a resist layer 23B (second resist layer) is formed around the position facing the opening 13A. It is formed in a ring shape (FIG. 15).

  The widths R1 and R2 of the resist layers 23A and 23B are set by reflow and resist etch-back so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A. Specifically, the widths R1 and R2 of the resist layers 23A and 23B are set based on the relationship shown in FIG. 3 so that the height of the protrusion 11B is equal to or greater than the height of the protrusion 11A.

  It is assumed that the width of the ring-shaped resist layer 23B used for forming the protrusion 11B is smaller than the diameter of the island-shaped resist layer 23A used for forming the protrusion 11A. For example, the width R1 of the resist layer 23A is set to 80 μm, and the width R2 of the resist layer 23B is set to 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the convex portion 11B formed by the ring-shaped resist layer 23B can be formed higher than the convex portion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A becomes 80 μm, the width of the projection 11B becomes 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B becomes smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the width of the ring-shaped resist layer 23B used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer 23A used for forming the protrusion 11A. For example, it is assumed that the width R1 of the resist layer 23A is 30 μm and the width R2 of the resist layer 23B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B formed by the island-shaped resist layer 23B can be formed higher than the protrusion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A becomes 30 μm, the width of the projection 11B becomes 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B becomes larger than the radius of curvature of the projection 11A.

  Next, reflow is performed on the resist layers 23A and 23B. As a result, the surface of the resist layer 23A is formed into a convex curved surface, and at least the end of the resist layer 23B on the side of the resist layer 23A is formed into a convex curved surface. For example, the entire surface of the resist layer 23A is formed into a convex curved surface, and the surface shape in the width direction of the resist layer 23B is formed into a convex curved surface. At this time, the height of the resist layer 23B is equal to or higher than the height of the resist layer 23A.

  Next, dry etching is performed on the substrate 11 using the resist layers 23A and 23B having a convex curved surface as a mask. That is, dry etching is performed on the substrate 11 by using the resist etch-back method using the reflowed resist layers 23A and 23B as a mask. At this time, it is preferable to make the etching rate of the substrate 11 and the etching rate of the resist layers 23A and 23B as equal as possible. By using such a resist etch-back method, it is possible to form convex portions 11A and 11B on the back surface of the substrate 11 that are very similar to the surface shapes of the resist layers 23A and 23B. Specifically, the convex portion 11A having a convex curved surface is formed at the position where the resist layer 23A is formed, and at least the end portion (inner periphery) on the side of the convex portion 11A is formed at the position where each resist layer 23B is formed. (A side end) can be formed as a convex portion 11B having a convex curved surface. As a result, the height of the protrusion 11B is equal to or higher than the height of the protrusion 11A.

  Next, effects of the light emitting element 1 of the present modification will be described.

  In the present modified example, on the surface of the substrate 11 opposite to the laminate 12, there is provided a convex-curved convex portion 11A that is in contact with the DBR layer 18 and faces the opening 13A. The substrate 11 is further provided with a ring-shaped protrusion 11B having a height equal to or higher than the height of the protrusion 11A around the protrusion 11A. In the ring-shaped convex portion 11B, at least the surface of the end portion (the inner peripheral end portion) on the convex portion 11A side has a convex curved shape. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function of the convex curved surface of the metal layer 19 (the convex portion 10B) formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. As a result, the alignment of the light emitting element 1 with respect to the wiring board 30 can be performed accurately, and the DBR layer 18 can be protected.

  In this modification, the convex portion 11A has an island shape, and the convex portion 10B has a ring shape. Thereby, for example, by performing the resist etchback using the relationship shown in FIG. 3, not only the height of the protrusion 11B can be made higher than the height of the protrusion 11A, but also the protrusion 11A and the protrusion 11B are collectively formed. Can be formed. As a result, the light emitting element 1 can be accurately positioned with respect to the wiring board 30 without increasing the number of manufacturing procedures, and the DBR layer 18 can be protected. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In this modification, in the manufacturing process, reflow is performed on the island-shaped resist layer 23A and the ring-shaped resist layer 23B provided on the back surface of the substrate 11. Thereby, the surface of the resist layer 23A has a convex curved surface, and at least the surface of the resist layer 23B on the side of the resist layer 23A (the inner peripheral end) has a convex curved surface. Further, dry etching using a resist etch-back method is performed using the resist layers 23A and 23B after the reflow as a mask. As a result, on the back surface of the substrate 11, a convex portion 11A having a convex curved surface is formed at the position where the resist layer 23A was formed, and at least the end portion (at the resist layer 23A side) at the position where the resist layer 23B is formed. A convex portion 11B having a convex curved surface is formed on the surface of the inner peripheral end). The widths R1 and R2 of the resist layer 23A and the resist layer 23B are set by reflow and resist etch-back so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function by the convex curved surface of the metal layer 19 formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. Therefore, it is possible to accurately position the light emitting element 1 with respect to the wiring substrate 30 without increasing the number of manufacturing procedures, and to protect the DBR layer 18. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  Further, in this modification, in the manufacturing process, one resist layer 23A is formed, one resist layer 23B is formed, the resist layer 23A is formed in an island shape, and the resist layer 23B is formed in a ring shape. Formed. Thereby, the height of the convex portion 11B can be made higher than the height of the convex portion 11A only by setting the respective widths R1 and R2 of the resist layer 23A and the resist layer 23B to desired values. Therefore, it is possible to accurately position the light emitting element 1 with respect to the wiring substrate 30 without increasing the number of manufacturing procedures, and to protect the DBR layer 18. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

[Modification B]
FIG. 16 illustrates a modification of the light-emitting element 1. In this modified example, two or more convex portions 11B are provided. In the present modified example, the plurality of protrusions 11B have a shape and layout in which an annular protrusion is divided into a plurality. Each projection 11B has a straight rod shape or a curved rod shape. The plurality of protrusions 11B are provided so as to avoid positions facing the openings 13A, and are provided around the protrusions 11A. The plurality of protrusions 11B are arranged, for example, at point-symmetric positions with respect to the protrusion 11A. Each projection 11B has a height equal to or higher than the height of the projection 11A, and at least the surface of the end on the side of the projection 11A has a convex curved shape. The entire surface of each convex portion 11B may have a convex curved surface shape protruding to the opposite side to the laminate 12 in the width direction of the convex portion 11B.

  The height of the protrusion 11B is formed by etching the substrate 11 using the reflowed bar-shaped resist layer as a mask, as described later. The width of the reflowed bar-shaped resist layer corresponds to the lens diameter in FIG. That is, by changing the width of the reflowed bar-shaped resist layer, the height and the radius of curvature in the width direction of the protrusion 11B can be adjusted.

  A design is assumed in which the width of the bar-shaped resist layer used for forming the protrusion 11B is smaller than the diameter of the island-shaped resist layer used for forming the protrusion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the protrusion 11A is 80 μm, and the width of the bar-shaped resist layer used for forming the protrusion 11B is 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A becomes 80 μm, the width of the projection 11B becomes 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B becomes smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the width of the bar-shaped resist layer used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer used for forming the protrusion 11A. For example, it is assumed that the diameter of the island-shaped resist layer used for forming the protrusion 11A is 30 μm, and the width of the bar-shaped resist layer used for forming the protrusion 11B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B can be formed higher than the protrusion 11A. At this time, the diameter of the projection 11A becomes 30 μm, the width of the projection 11B becomes 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B becomes larger than the radius of curvature of the projection 11A.

  The protrusions 11A and 11B are formed, for example, as follows. First, as shown in FIG. 8, the back surface of the substrate 11 is mirror-finished. Next, a resist pattern is formed on the back surface of the polished substrate 11. As a result, a resist layer 23A (first resist layer) is formed in an island shape at a position facing the opening 13A, and each resist layer 23B (second resist layer) is formed around the position facing the opening 13A. Is formed so as to have a shape and layout in which the annular convex portion is divided into a plurality of portions (FIG. 17).

  The widths R1 and R2 of the resist layers 23A and 23B are set by reflow and resist etch-back so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A. Specifically, the widths R1 and R2 of the resist layers 23A and 23B are set based on the relationship shown in FIG. 3 so that the height of the protrusion 11B is equal to or greater than the height of the protrusion 11A.

  It is assumed that the width of the rod-shaped resist layer 23B used for forming the protrusion 11B is smaller than the diameter of the island-shaped resist layer 23A used for forming the protrusion 11A. For example, the width R1 of the resist layer 23A is set to 80 μm, and the width R2 of the resist layer 23B is set to 30 μm or more and 70 μm or less. At this time, according to FIG. 3, the protrusion 11B formed by the bar-shaped resist layer 23B can be formed higher than the protrusion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A becomes 80 μm, the width of the projection 11B becomes 30 μm or more and 70 μm or less, and the radius of curvature of the surface of the projection 11B becomes smaller than the radius of curvature of the projection 11A.

  Next, a design is assumed in which the width of the bar-shaped resist layer 23B used for forming the protrusion 11B is larger than the diameter of the island-shaped resist layer 23A used for forming the protrusion 11A. For example, it is assumed that the width R1 of the resist layer 23A is 30 μm and the width R2 of the resist layer 23B is 40 μm or more and 60 μm or less. At this time, according to FIG. 3, the protrusion 11B formed by the bar-shaped resist layer 23B can be formed higher than the protrusion 11A formed by the island-shaped resist layer 23A. At this time, the diameter of the projection 11A becomes 30 μm, the width of the projection 11B becomes 40 μm or more and 60 μm or less, and the radius of curvature of the surface of the projection 11B becomes larger than the radius of curvature of the projection 11A.

  Next, reflow is performed on the resist layers 23A and 23B. As a result, the surface of the resist layer 23A is formed into a convex curved surface, and at least the end of the resist layer 23B on the side of the resist layer 23A is formed into a convex curved surface. For example, the entire surface of the resist layer 23A is formed into a convex curved surface, and the surface shape in the width direction of the resist layer 23B is formed into a convex curved surface. At this time, the height of the resist layer 23B is equal to or higher than the height of the resist layer 23A.

  Next, dry etching is performed on the substrate 11 using the resist layers 23A and 23B having a convex curved surface as a mask. That is, dry etching is performed on the substrate 11 by using the resist etch-back method using the reflowed resist layers 23A and 23B as a mask. At this time, it is preferable to make the etching rate of the substrate 11 and the etching rate of the resist layers 23A and 23B as equal as possible. By using such a resist etch-back method, it is possible to form convex portions 11A and 11B on the back surface of the substrate 11 that are very similar to the surface shapes of the resist layers 23A and 23B. Specifically, the convex portion 11A having a convex curved surface is formed at the position where the resist layer 23A is formed, and at least the end portion (inner periphery) on the side of the convex portion 11A is formed at the position where each resist layer 23B is formed. (A side end) can be formed as a convex portion 11B having a convex curved surface. As a result, the height of the protrusion 11B is equal to or higher than the height of the protrusion 11A.

  Next, effects of the light emitting element 1 of the present modification will be described.

  In the present modified example, on the surface of the substrate 11 opposite to the laminate 12, there is provided a convex-curved convex portion 11A that is in contact with the DBR layer 18 and faces the opening 13A. The substrate 11 further includes a plurality of bar-shaped protrusions 11B having a height equal to or higher than the height of the protrusions 11A around the protrusions 11A. In each of the bar-shaped protrusions 11B, at least the surface of the end on the protrusion 11A side has a convex curved shape. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function of the convex curved surface of the metal layer 19 (the convex portion 10B) formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. As a result, the alignment of the light emitting element 1 with respect to the wiring board 30 can be performed accurately, and the DBR layer 18 can be protected.

  In this modification, the convex portion 11A has an island shape, and the convex portion 10B has a bar shape. Thereby, for example, by performing the resist etchback using the relationship shown in FIG. 3, not only the height of the protrusion 11B can be made higher than the height of the protrusion 11A, but also the protrusion 11A and the protrusion 11B are collectively formed. Can be formed. Further, since there is a gap between two adjacent protrusions 10B, for example, when polishing the protrusion 11A by CMP or the like, it is possible to control the position where the polishing liquid is poured by using the gap. . Therefore, it is possible to make an adjustment such as distorting the shape of the convex portion 11A or bringing the shape of the convex portion 11A closer to axial symmetry without increasing the manufacturing procedure. Further, the DBR layer 18 can be protected by the convex portions 11A and 11B. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In the present modification, in the manufacturing process, reflow is performed on the island-shaped resist layer 23A and the bar-shaped resist layer 23B provided on the back surface of the substrate 11. Thereby, the surface of the resist layer 23A becomes a convex curved surface, and at least the surface of the end portion on the resist layer 23A side of the surface of the resist layer 23B becomes a convex curved surface. Further, dry etching using a resist etch-back method is performed using the resist layers 23A and 23B after the reflow as a mask. As a result, on the back surface of the substrate 11, a convex curved portion 11A is formed at the place where the resist layer 23A was formed, and at least the end of the resist layer 23A side is formed at the place where the resist layer 23B is formed. A convex portion 11B having a convex curved surface is formed. The widths R1 and R2 of the resist layer 23A and the resist layer 23B are set by reflow and resist etch-back so that the height of each protrusion 11B is equal to or greater than the height of the protrusion 11A. Thus, the mounting position of the light emitting element 1 is determined by the self-alignment function by the convex curved surface of the metal layer 19 formed following the convex curved surface of the convex portion 11B. In the manufacturing process and the mounting process of the light emitting element 1, the convex portion 11A is protected by the convex portion 11B. Therefore, it is possible to accurately position the light emitting element 1 with respect to the wiring substrate 30 without increasing the number of manufacturing procedures, and to protect the DBR layer 18. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

  In this modification, in the manufacturing process, one resist layer 23A is formed, two or more resist layers 23B are formed, the resist layer 23A is formed in an island shape, and the resist layer 23B is It is formed into a shape. Thereby, the height of the convex portion 11B can be made higher than the height of the convex portion 11A only by setting the respective widths R1 and R2 of the resist layer 23A and the resist layer 23B to desired values. Therefore, it is possible to accurately position the light emitting element 1 with respect to the wiring substrate 30 without increasing the number of manufacturing procedures, and to protect the DBR layer 18. In addition, since the protrusions 11A and the protrusions 10B can be formed at the same time, deterioration of roughness due to damage due to unnecessary etching can be avoided. Thereby, diffraction loss due to deterioration of roughness can be suppressed, and cracks and the like due to stress concentration can be suppressed.

[Modification C]
FIG. 18 illustrates a modification of the light emitting device 1 of FIG. FIG. 19 illustrates an example of a top configuration of the light-emitting element 1 in FIG. FIG. 20 illustrates a modification of the light emitting device 1 of FIG. FIG. 21 illustrates a modification of the light emitting device 1 of FIG.

  The light-emitting element 1 of this modification corresponds to the light-emitting element 1 of the above embodiment, in which a bump 20 (bump metal) is further provided at a position facing the protrusions 11B and 11C. The bump 20 is provided, for example, in a through hole penetrating the DBR layer 18 and the metal layer 19. The height of the bump 20 is equal to or higher than the height of the protrusion 10A. Here, the height of the bump 20 refers to the height from the flat surface 11S corresponding to the base of the projection 11A on the back surface of the substrate 11. Even in the case of such a configuration, the bump 20 exhibits the same function as the convex portions 10B and 10C of the above embodiment. As a result, the alignment of the light emitting element 1 with respect to the wiring board 30 can be performed accurately, and the DBR layer 18 can be protected.

  As described above, the present disclosure has been described with reference to the embodiment and the modifications thereof. However, the present disclosure is not limited to the above-described embodiment and the like, and various modifications are possible. Note that the effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure may have effects other than those described herein.

Further, for example, the present disclosure can have the following configurations.
(1)
An active layer, a stacked body including a first semiconductor layer and a second semiconductor layer sandwiching the active layer;
A current confinement layer having an opening;
A concave curved first reflecting mirror on the first semiconductor layer side and a second reflecting mirror on the second semiconductor layer side, sandwiching the laminate and the opening;
A light-transmitting substrate provided between the first reflecting mirror and the laminate,
The light-transmitting substrate is on a surface opposite to the laminate,
A first convex portion having a convex curved surface in contact with the first reflecting mirror;
One or more second protrusions provided around the first protrusion and having a height equal to or higher than the height of the first protrusion and having an end on the side of the first protrusion having a convex curved shape. A light emitting element having a projection and a projection.
(2)
The light emitting device according to (1), wherein the second reflecting mirror is formed so as to follow a surface including surfaces of the first convex portion and the second convex portion.
(3)
The light emitting device according to (2), wherein the light emitting device further includes a metal layer formed following the surface of the second reflecting mirror.
(4)
The light transmissive substrate has a plurality of the second convex portions,
The light emitting device according to any one of (1) to (3), wherein each of the second convex portions has an island shape.
(5)
The light transmissive substrate has one of the second protrusions,
The light emitting device according to any one of (1) to (3), wherein the second convex portion has an annular shape.
(6)
The light transmissive substrate has a plurality of the second convex portions,
The light emitting device according to any one of (1) to (3), wherein the plurality of second convex portions have a shape and layout in which an annular convex portion is divided into a plurality of portions.
(7)
The light emitting device according to any one of (1) to (6), further including a bump metal formed at a position facing the second convex portion.
(8)
The light emitting device according to any one of (1) to (7), wherein the light transmitting substrate is a GaN substrate.
(9)
A light emitting device including, on a first main surface of a light transmitting substrate, an active layer, a laminate including a first semiconductor layer and a second semiconductor layer sandwiching the active layer, and a current confinement layer having an opening. In the substrate, a first resist layer is formed on a second main surface of the light-transmitting substrate opposite to the first main surface at a location facing the opening and faces the opening. A resist forming step of forming one or more second resist layers around the location;
The first resist layer and one or more of the second resist layers are reflowed so that the surface of the first resist layer becomes a convex curved surface and one or more of the second resist layers are formed. A reflow step of making at least the first resist layer side end of the surface a convex curved surface;
By performing dry etching using a resist etch-back method using the first resist layer after the reflow and the one or more second resist layers as a mask, the second main surface of the substrate is A first convex portion having a convex curved surface is formed at a position where the first resist layer is formed, and at least one end on the first resist layer side is formed at a position where one or a plurality of the second resist layers are formed. A convex portion forming step of forming a second convex portion having a convex curved surface.
In the resist forming step, the width of each of the first resist layer and one or a plurality of the second resist layers is set such that the height of each of the second convex portions is the first convex by the reflow and the resist etchback. The method for manufacturing a light emitting element, which is set to be equal to or higher than the height of the portion.
(10)
In the resist forming step, one first resist layer is formed, two or more second resist layers are formed, and the first resist layer and each of the second resist layers are formed in an island shape. The method for manufacturing a light emitting device according to (9).
(11)
In the resist forming step, one first resist layer is formed, one second resist layer is formed, and further, the first resist layer is formed in an island shape, and the second resist layer is formed. The method for manufacturing a light-emitting element according to (9), wherein the light-emitting element is formed in an annular shape.
(12)
In the resist forming step, one first resist layer is formed, two or more second resist layers are formed, and the first resist layer is formed in an island shape. The method for manufacturing a light-emitting element according to (9), wherein the layer is formed so as to have a shape and layout in which an annular convex portion is divided into a plurality.

  This application claims priority based on Japanese Patent Application No. 2017-107830 filed on May 31, 2017 by the JPO, and hereby incorporated by reference in its entirety. Incorporated into application.

  Various modifications, combinations, subcombinations, and modifications may occur to those skilled in the art, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that it is.

Claims (12)

An active layer, a stacked body including a first semiconductor layer and a second semiconductor layer sandwiching the active layer;
A current confinement layer having an opening;
A concave curved first reflecting mirror on the first semiconductor layer side and a second reflecting mirror on the second semiconductor layer side, sandwiching the laminate and the opening;
A light-transmitting substrate provided between the first reflecting mirror and the laminate,
The light-transmitting substrate is on a surface opposite to the laminate,
A first convex portion having a convex curved surface in contact with the first reflecting mirror;
One or more second protrusions provided around the first protrusion and having a height equal to or higher than the height of the first protrusion and having an end on the side of the first protrusion having a convex curved shape. A light emitting element having a projection and a projection. The light emitting device according to claim 1, wherein the second reflecting mirror is formed following a surface including surfaces of the first convex portion and the second convex portion. The light emitting device according to claim 2, wherein the light emitting device further includes a metal layer formed following the surface of the second reflecting mirror. The light transmissive substrate has a plurality of the second convex portions,
The light emitting device according to claim 1, wherein each of the second convex portions has an island shape. The light transmissive substrate has one of the second protrusions,
The light emitting device according to claim 1, wherein the second convex portion has an annular shape. The light transmissive substrate has a plurality of the second convex portions,
The light emitting device according to claim 1, wherein the plurality of second protrusions have a shape and a layout in which an annular protrusion is divided into a plurality. The light emitting device according to claim 2, further comprising a bump metal formed at a position facing the second convex portion. The light emitting device according to claim 1, wherein the light transmissive substrate is a GaN substrate. A light emitting device including, on a first main surface of a light transmitting substrate, an active layer, a laminate including a first semiconductor layer and a second semiconductor layer sandwiching the active layer, and a current confinement layer having an opening. In the substrate, a first resist layer is formed on a second main surface of the light-transmitting substrate opposite to the first main surface at a location facing the opening and faces the opening. A resist forming step of forming one or more second resist layers around the location;
The first resist layer and one or more of the second resist layers are reflowed so that the surface of the first resist layer becomes a convex curved surface and one or more of the second resist layers are formed. A reflow step of making at least the first resist layer side end of the surface a convex curved surface;
By performing dry etching using a resist etch-back method using the first resist layer after the reflow and the one or more second resist layers as a mask, the second main surface of the substrate is A first convex portion having a convex curved surface is formed at a position where the first resist layer is formed, and at least one end on the first resist layer side is formed at a position where one or a plurality of the second resist layers are formed. A convex portion forming step of forming a second convex portion having a convex curved surface.
In the resist forming step, the width of each of the first resist layer and one or a plurality of the second resist layers is set such that the height of each of the second convex portions is the first convex by the reflow and the resist etchback. The method for manufacturing a light emitting element, which is set to be equal to or higher than the height of the portion. In the resist forming step, one first resist layer is formed, two or more second resist layers are formed, and the first resist layer and each of the second resist layers are formed in an island shape. A method for manufacturing the light emitting device according to claim 9. In the resist forming step, one first resist layer is formed, one second resist layer is formed, and further, the first resist layer is formed in an island shape, and the second resist layer is formed. The method for manufacturing a light emitting device according to claim 9, wherein the light emitting device is formed in a ring shape. In the resist forming step, one first resist layer is formed, two or more second resist layers are formed, and the first resist layer is formed in an island shape. The method for manufacturing a light-emitting element according to claim 9, wherein the layer is formed so as to have a shape and a layout in which an annular convex portion is divided into a plurality.